Configuration Guidelines for Sun Cluster Data Services

Identifying Data Service Special Requirements

Identify requirements for all of the data services before you begin Solaris and Sun Cluster installation. Failure to do
so might result in installation errors that require that you completely reinstall
the Solaris and Sun Cluster software.

For example, the Oracle Parallel Fail Safe/Real Application Clusters Guard option of Sun Cluster Support for Oracle Parallel Server/Real Application Clusters has special requirements
for the hostnames that you use in the cluster. Sun Cluster HA for SAP also has special requirements.
You must accommodate these requirements before you install Sun Cluster software
because you cannot change hostnames after you install Sun Cluster software.

Note –

Some Sun Cluster data services are not supported for use in
x86 based clusters. For more information, see the release notes for your release
of Sun Cluster at http://docs.sun.com.

Determining the Location of the Application Binaries

You can install the application software and application configuration files
on one of the following locations.

The local disks of each cluster node – Placing the software and configuration files on the individual cluster
nodes provides the following advantage. You can upgrade application software later
without shutting down the service.

The disadvantage is that you then have
several copies of the software and configuration files to maintain and administer.

The cluster file system – If
you put the application binaries on the cluster file system, you have only one copy
to maintain and manage. However, you must shut down the data service in the entire
cluster to upgrade the application software. If you can spare a short period of downtime
for upgrades, place a single copy of the application and configuration files on the
cluster file system.

Highly available local file system – Using HAStoragePlus, you can integrate your local
file system into the Sun Cluster environment, making the local file system highly
available. HAStoragePlus provides additional file system capabilities
such as checks, mounts, and unmounts that enable Sun Cluster to fail over local
file systems. To fail over, the local file system must reside on global disk groups
with affinity switchovers enabled.

Verifying the nsswitch.conf File
Contents

The nsswitch.conf file is the configuration file for name-service
lookups. This file determines the following information.

The databases within the Solaris environment to use for name-service
lookups

The order in which the databases are to be consulted

Some data services require that you direct “group” lookups to “files”
first. For these data services, change the “group” line in the nsswitch.conf file so that the “files” entry is listed first.
See the documentation for the data service that you plan to configure to determine
whether you need to change the “group” line.

Planning the Cluster File System Configuration

Depending on the data service, you might need to configure the cluster file
system to meet Sun Cluster requirements. To determine whether any special considerations
apply, see the documentation for the data service that you plan to configure.

The resource type HAStoragePlus enables you to use a highly
available local file system in a Sun Cluster environment that is configured for failover.
For information about setting up the HAStoragePlus resource type,
see Enabling Highly Available Local File Systems.

Enabling Solaris SMF Services to Run Under the Control of Sun Cluster

You might require Sun Cluster to make highly available an application other
than NFS or DNS that is integrated with the Solaris Service Management Facility (SMF).
To ensure that Sun Cluster can restart or fail over the application correctly after
a failure, you must disable SMF service instances for the application as follows:

For any application other than NFS or DNS, disable the SMF service
instance on all potential primary nodes for the Sun Cluster resource that represents
the application.

If multiple instances of the application share any component that
you require Sun Cluster to monitor, disable all service instances of the application.
Examples of such components are daemons, file systems, and devices.

Note –

If you do not disable the SMF service instances of the application, both
the Solaris SMF and Sun Cluster might attempt to control the startup and shutdown
of the application. As a result, the behavior of the application might become unpredictable.